The general goal of this project is to understad the structure, function, and physiology of the glycoprotein hormones-thyrotropin, chorionic gonadotropin, luteinizing hormone and follicle-stimulating hormone--and to elucidate the role of glycoprotein hormone derangements in human diseases. Recent research findings include the following: demonstration of the clinical value of a highly sensitive urinary chorionic gonadotropin assay in the management of patients with gestational trophoblastic neoplasia; characterization of the heterogeneous nature of chorionic gonadotropin preparations used by physicians in hypogonadotropic patients; and elucidation of a role for prostaglandins in mediating an immunosuppressive effect of chorionic gonadotropin. Future emphasis of the project will be on structure-activity relationships of glycoprotein hormone binding sites in thyroid membranes, metabolic disposal and degradation products of glycoproteins, and the clinical relevance of hormonal heterogeneity.